Verification and Validation of Hybridspectral Radiometry Obtained from an Unmanned Surface Vessel (USV) in the Open and Coastal Oceans

Stanford B Hooker,Henry F Houskeeper,Randall N Lind,Raphael M Kudela,Koji Suzuki

doi:10.3390/rs14051084

Abstract

The hardware and software capabilities of the compact-profiling hybrid instrumentation for radiometry and ecology (C-PHIRE) instruments on an unmanned surface vessel (USV) are evaluated. Both the radiometers and USV are commercial-off-the-shelf (COTS) products, with the latter being only minimally modified to deploy the C-PHIRE instruments. The hybridspectral C-PHIRE instruments consist of an array of 18 multispectral microradiometers with 10 nm wavebands spanning 320–875 nm plus a hyperspectral compact grating spectrometer (CGS) with 2048 pixels spanning 190–1000 nm. The C-PHIRE data were acquired and processed using two architecturally linked software packages, thereby allowing lessons learned in one to be applied to the other. Using standard data products and unbiased statistics, the C-PHIRE data were validated with those from the well-established compact-optical profiling system (C-OPS) and verified with the marine optical buoy (MOBY). Agreement between algorithm variables used to estimate colored dissolved organic matter (CDOM) absorption and chlorophyll a concentration were also validated. Developing and operating novel technologies, such as the C-PHIRE series of instruments, deployed on a USV increase the frequency and coverage of optical observations, which are required to fully support the present and next-generation validation exercises in radiometric remote sensing of aquatic ecosystems.

Highlights

Publisher’s Note: MDPI stays neutralAs ocean-observing satellites age, replacements are a critical requirement to maintain a quality assured time series of planetary climate [1], typically referred to as a climate data record (CDR)
The focus of this study is to evaluate the efficacy of hybridspectral radiometers to derive apparent optical properties (AOPs) data products
The approach uses a combination of calibration and in situ data wherein the different detector systems are compared as a function of increasing data product complexity

Summary

Introduction

As ocean-observing satellites age, replacements are a critical requirement to maintain a quality assured time series of planetary climate [1], typically referred to as a climate data record (CDR). Missions [2] and beyond is an international activity shared between space agencies launching new satellites and researchers who vicariously calibrate the spaceborne radiances, subsequently validating the algorithms used to derive data products, and pursue original research. This calibration, validation, and research (CVR) triad determines mission success and establishes the requirements for follow-on missions. The Protocols include with regard to jurisdictional claims in published maps and institutional affiliations

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